Grinding machine



. June 24 .1924;

F; a GABQNR aanname MAHms fue@ Aug. 9, 1919 4 swans-'sheen 1 GRINDING MACHINE Filed Aug. 9 1919 4 Sheets-Sheet 2 me 24 1924. 1,499,104l

F. E. GARDNER GRINDING MACHINE Fled Aug. 9. 1919 4 -sheetsfsheet if June 24 -1924. 1,4995104 F, E. GARDNER GRINDING MACHINE Filed Aug. 9 '1919 4 Sheets-Sheet 4 atented .lune 24, 1924.

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a F ICE rnnnnnrc n. een-nnen, on annoia, wisconsin.

GRINDING MACHNE.

Application lcd August 9, 1919.

T all erizo/m. it' 'may concern.'

Be it known that l, Fnunnnrc E. GARDNER, a citizen oit' the United States, residing` at Beloit, in the county of Rock and State of llisconsin, have invented certain new and useful Improvements in Grinding Machines, of which the following is a specification. Y

This invention relates to the art of grinding machines and refers more especially to machines of the type comprising two rotary grinding wheels between which articles of work to be ground are fed for grinding opposite faces of such articles.

The general object4 of the invention is to produce a grinding machine of very high accuracy which is automatic in its operation so that one operator can attend to several machines in operation in a shop or factory.

More particularly stated, one orn the objects of the invention is to produce a grinding machine in which the grinding elements are mounted in offset or staggered relationship so that they overlap or oppose each other over only a portion of their working faces, leaving` another portion of. each element eX- posed so as to facilitate dressing the elenient.

luiother object of the invention is to provide a novel and improved means for feeding the work between the grinding elements and further to provide for the automatic oper; tion of the feeding means.

Another object is to effect a periodical or intermittent retracting and approaching` movement Aof one of the grinding elements with relation to the other for the purpose of temporarily increasing the space between said elements so as to facilitate the admission of the articles of work; and in this connection it is a further object to produce a mechanism for effecting this retracting and approaching` movement of said element in timed relation `to the automatic work-feeding means so that the grinding elements will be separated temporarily for the adn'iission of the successive pieces of work.

Further and ancillary objects relating to the construction and advantages of the ma- .ehinewill be fully set forth in the following detailed description.

Certain features of the machine disclosed herein are covered in my copending application Serial No. 472,977, filed May 27 1921. In the accompanying drawings, Fig. 1is a side and Fig. 2 anend elevation of nia- SeliaI No. 316,281.

chine embodying' the principles of my invention. Fig. 3 is a plan view of the same iachine. Fig. 4 is a partial side view broken away to the center line of the recipro-A cating carriage. 5 is a section On the line 5-5 of Fig. 4.

ln the embodiment of my invention selected for illustration, a suitable base carries on its opposite ends `two carriages 11v and 12 equipped with grinding wheels 18 and 14 on the longitudinally extending shafts 15 and 16, driven by means of pulleys 17 and 18 from any suitable source of power (not shown). rPhe aries of the two shafts 15 and 16 are offset out of alinement with each other as indicated in F ig. 3 so that the grinding wheels 13 and 14 only face each other over a relatively small area in the center of the machine. Between the wheels 13 and 14, there is mounted a rotatable work-carrier 19 which in the form herein shown consists of a circular disk adapted to receive small flat objects in suitable holes 2O uniformly spaced adjacent its periphery and carry them down between the grinding wheels, where they are ground, and then up to a discharge chute 27. Pieces to be ground indicated at- 22 in Fig. 1 are piled in an inclined chute v23 terminating adjacent the face of the carrier V19. As the carrier rotates vpast the end of the chute the lower-most piece will fall into the hole in the carrier and be carried down in front of the grinding wheel 13, being restrained from falling out of the hole by a suitable guide plate 24 opposite the chute 23 and an arcuate shield 25 located below said chute opposite the wheel14. As the piece of work is lcarried down between the opposed faces of the grinding elements by the rotation of the carrier, the carriage 11 is automatically drawn back to let the pie-ce of work enter freely. After the work is entirely between the opposed portions of the faces of the grinding wheels, the carriage 11 is automatically fed in andthe piece is ground to an exact thickness. `rllhe carriage is then drawn back again and the finished piece is carried up across the face of .the wheel 13, being restrained from falling out of its hole by a suitable arcuate shield 26 until Ait reach-es the discharge chute 27 into which vit falls and by which is conveyed to a suitable receptacle (not shown). The {inished piece moves out and a new piece is moved in at each retraction of the carriage 11,

loo

The automatic means for rotating the carrier 1S) and reciprocating the carriage 11 Will next be described. A drive shaft 28 carrying acone of pulleys 29 is driven by any suitable source of power (not shown). A Worm 30` on the drive shaft 28 engages a Worm ivheel 31 on a vertical shaft 32 mounted in stationary bearings in the base and carrying at its upper end a cam or eccentric 33. The carriage 11 is slidably mounted on Ways 34 on the sub-base which is pressed toward the Work by a powerful coil spring 36 compressed between the end of the carriage and an adjustable buttplate 3T carried by the set screwv 38 in a suitable bracket 39 projecting from the base 10.

A. pin 40 in the Hoor of the sub-base 35 carries a roller 41 adapted to be engaged by the eccentric or cam` 33 whereby the subbase and carriage may be forced away from the Work. To secure greater accuracy in allowing the sub-base to move forward under the force of the spring 36 to a certain point than can be secured byV a roller such as 41 which is subject to considerable Wear, l provide a stop bar 42 notched into the Ways 43 on which the sub-base 35 slides on the base 10, and suitably fastened in place as by screws 44. One face of the bar 42 abuts against the outer side of the channel 44a in the floor of the sub-base 35 to limit the motion of the sub-base toward the Work. It Will be seen that these surfaces have no sliding motion but are merely laid face to face against each other and separated again by the action of the cam. The Wear on them is therefore inappreciable and a very high degree of accuracy in the motion of the sub-base and carriage can be secured.

For operating the carrier 19 in synchronism with the: reciprocation of the carriage 11 so that the carriage will be'moved outward each time a piece of Work is to 'be fed between the opposed portions of the faces of the grinding element, a pair of bevel gears 45 drive' the horizontal shaft 4G from the vertical shaft 32. Spur gears 47 and 43 drive a second horizontal shaft 49 extending along` the center line ofthe machine and at its inner end carrying a drive disk The two disks 50 and 19 have intermeshing gear teeth so that the carrier 19 is driven b v the power disk 50. These disks must obviously be of less thickness than the thickness of the Work being ground. Their intermcshing teeth engage each other just below the piece of Work Whilefit is' being ground and are exposed to the grit and dirt produced by the grinding operation. journaled in alined bearings 51 and 52 carried by opstanding arms 53 and 54 each arm offset as shown to clear the adjacent grinding Wheel. To prevent particles of grit or other obstacles from breaking some The carrier 19 isV part of the machine. the journals 51 and 52 are vertically slotted allowing a very slight vertical motion of the Work carrier. The grinding Wheels 13 and 14 are rotated so as to press down upon the Work they are grinding and this pressure as Well as the Weight of the carrier 19 is carried by the drive disk 50. The upper journals 51 and 52 merely maintain the axis of the carrier exactly in the vertical central plane of the machine and approximately horizontal^ rIhe movement of the reciprocating subbase 35 and carriage 11 is guided by the Ways 34 and 43. and their alinement on the base 10 can not be changed after the machine has been assembled. Means are provided for securing perfect parallelism of the axes of the two grinding Wheels by adjustment of the second carriage 12. A knee 53 is journaled on a horizontal axis at 54 on the base of the machine and supported at. its outer end at 55 by a threaded rod 56 and an adjusting nut engaging a suitable surface on the base. A. sub-base is adapted to be clamped in position on the knee by four bolts 57, 58, 59 and 60 passing through alined lugs on the sub-base and the knee respectively. rlhe lugs for the bolt 60 have round holes fitting the bolt Whereas one of the lugs for each of the other bolts 57:, 53 and has an arcuate slot to allen7 a small amount of rotation of the entire sub-base 12 around the bolt GO as a center. Suitable upstanding lugs 61 and G2 on either side of the knee 53 carry adjusting 'bolts G3 by means of which when the main bolts 57. 59 and 60 are loosened, the sub-base 53 can be conveniently and accurately adjusted in the exact alinement in the horizontal plane. It Will be seen that these tivo adjustments completely provide for perfect alinement of the tivo grinding elements.

For adjusting one or both of the `grinding elements 13 and 14 with respect to the Work, each carriage l1 and 12 is slidably mounted With respect to its sub-base 35 and 53 respectively, by Ways 34 and 64. The n'icans for making this adjustment comprises in each instance a nut 65 (see Fig. 4) embodying a Worm Wheel 6G meshing with a transverse Worm 67 and engaged between opposed faces of the carriage Y1l or 12 carrying the grinding element. A screw-threaded shaft 68 passes through the nut 65 in suitable engagement therewith and is restrained from axial movement by suitable collars 69 engaging an upstanding lug 70 on the sub-base. For quick adjustment of the grinding element, the shaft 68 is rotated Within the nut by means of a handle 71. A slower and much more accurate adjustment is obtainable by clamping the shaft by means of the clamping bolt 72 and rotating the nut by means of the transverse Worm 67 which projects 'laterally from the carriage 11 or 12 and bears a suitable knurled hand wheel 73. In changing from one size of'y work to another it is convenient Yto use the quick adjustment foran approximate setting of the machine after which it may be tightened and exact adjustment as Well as readjustment Whenever necessary to compensate for the wear of the grinding element may be obtained by means of the hand wheel 73.

For work of the highest degree of accuracy, frequent or sometimes practically continuous dressing of the grinding element may be necessary. The offset arrangement of 'the grinding wheels is wpeculiarly advantageous in that it permits such a dressing operation to be performed by a simple attachment at any 'time without disturbing the operation or adjustment of the machine as a whole. Referring to Figs. 1 and 2, the subbase has an integrally formed extension 74 laterally offset and extending past the grinding element 13. A suitable frame 7 5 bolted on the extension 74 carries a dressing device which may be of any desired form. I havepill'ustrated Va transversely slidable member 76 actuated by a suitable hand wheel 77 adapted to carry 'a dressing tool past the face ofthe grinding element. The common type ofdi'a'mond dressing tool may be mounted in the bore 78 for kadjustment toward and away from the grinding element. The sub-base 53 has a duplicate `extension 7 9 and dressing device which need not be further described in detail. It will be seen that the dressing tools may operate on Athe outerside of the grinding elements to eectively ldress the entire Working surface thereof `at any time. This mightbe 'done simultaneously with the operation of the lmachine to 'grind a piece of work. Y i

The device I have disclosed is very eiiicient, turning out large numbers 'of duplicate machine parts with a very high degree of accuracyanduniformity.V It embodies all the necessary adjustments 'to maintainl this accuracy and uniformity in spite of wear due to use. It will operate entirely automatically as long as asu'pply of materialis keptin the feed chute, so that the continuous attention of the operator is not essential.

While I have sh'own and described in detail the embodiment of my invention at present preferred it should be understood that the description is only for purposes of illustration and that many modifications and variations will naturally occur to those skilled in the art. I aim in the subjoined claims to cover all such legitimate modifications and variations.

I claim as my invention:

1. In a grinding machine, in combination, a frame, a grinding element rotatable on an axis extending longitudinally of said frame and oiiset from the center line thereof, a standard 011y Said hframe beside said grinding element extending up and 'over said element to support a bearing over the center line of the machine, a second grinding element rotatable on an axis offset on the other side of the center line of the machine from said first grinding element,V va second standard extending upwardly beside said second grinding element and over the same to support a second bearing over the center line of the machine, and a rotatable carrier mounted in said bearings adapted to support a piece Vof work and 'by its rotation to carry said piece of work past the center line of the machine between the opposed portions of the Vfaces of said grinding elements.

2. In a grinding machine, incombinationf,

3. The combination recited in claim 2 in combination with bearings for said upper disk, said bearings being slotted vertically to allow said disk to rise slightly whereby its weight may be Vcarried on the 'drive disk and whereby obstructions caught betweenk the interengaging faces of said disks will raise said upper disk rather than break the machine.

4. A vgrinding machine havin-g, in combina'tion, a base, two sub-bases carried` by said base offset in opposite directions from the longitudinal axis of said base, a longitudinally slidable carriage 'on each sub-base, rotatable grinding elements supported by said carriages and opposing each other centrally of the machine, manual means for adjusting thelongitudinal position of each carriage with respect vto its 'sub-base, power means' for reciprocating one -of said subbases and means for adjusting the'alinement ofthe other sub-base by rotation independently about each of two mutually perpendicular axes.

5. A `grinding machine having, in combination, a base, two sub-bases carried by said base and off-set in opposite directions from the longitudinal axis of said base, a longitudinally slidable carriage on each subbase, rotatable grinding elements supported by said carriages and opposing each other centrally of the machine, a standard opposite each grinding element extending upwardly in front of the other grinding element and inwardly to the center line of the machine t0 carry a rotatable Work carrier having a portion of its periphery passing between opposed portions of said grinding elements. i

6. The combination recitedgin claim 5 in combination with a drive disk engaging the lower portion of the periphery of said work carrier and adapted to rotate said work cai'- rier and also rto support the weight thereof.

7. The combination recited in claim 6 in combination with slotted bearings for said work carrier whereby said carrier may be allowed to rest upon saiddrive disk.

8. In a machine of the class described, the combination of a work holder, a main base on which said work holder is supported, a sub-base slidable on said main base, a carriage shiftable on said sub-base, *a grinding wheel structure journaled on said carriage to co-operate with the work holder to grind work, cam mechanism `engaging directly with said sub-base to shift it away from the work .lioldei, a spring for resisting outward movement of said base and for returning said sub-base inwardly when released from said cam mechanism, and a stop for limiting the inward movement of said subbase. Y

9. In a grinding machine of the class described, the combination of a main base, a work holder supported on said main base, a sub-base shiftable on said main base, a carriage structure shiftable on said sub-base, a grinding wheel structure journaled on said carriage to be bodily shifted therewith toward and away from said work holder as said sub-base is shifted, a cam roller on said sub-base, a cam engaging with said cam roller to shift said sub-base away from the work holder, a compression spring resisting such movement of the sub-base and serving to return said sub-base after release thereof from said cam wherebywork on the work holder will be applied under'spring pressure against said grinding wheel.

10. In a grinding machine of the class described, the combination of a main base, carriage structures mounted on the opposite ends of said main base, grinding elements supported on said carriage'structure for rotation, a revolvable work holder between said grinding elements having a plurality of work receiving openings, a standard on each side of said work holder supported on the main base, a shaft journaled in the upper ends of said standards for supporting said work holder between them, a feed chute supported on one of said standards for feeding articles into the work holder opening, and a chiite supported'on the other standard for receiving and discharging the ground articles.

Il. In a grinding machine of the class described, the combination of a main base, carriage structures adjustably mounted on said main base, grinding elen'ients rotatably supported on said carriage structures and opposed to each other, a revolvable work holder between said grinding elements, a standard on each side ofsaid work holder supported on said main base, a shaft journaled in the upper ends of said standards to which said work holder is secured, said work holder having a plurality of work receiving openings, a feed chute rmounted on one of said standards for feeding articles to be ground into the work holder openings as said work holder revolves, a guide plate on the other standard for holding articles in the work holder openings, and a discharge chute on said other standard for receiving and discharging ground articles.

l2. A grinding machine having, in coinbination, a base, a sub-base slidably mounted on said base, a rotatable grinding element supported on said sub-base, 1a secondv grinding element mounted opposite said first mentioned element, a carrier for moving work between said grinding elements at regular intervals, a cam roller mounted on said sub-base, a shaft journalled in said base and having a cam which engages said cam` roller, a horizontal shaft for driving the carrier said horizontal shaft being geared to said firstl mentioned shaft, and power means for driving said first mentioned shaft whereby a rotation of the carrier and a reciprocation of the first mentioned grinding element in timed relation is eifected.

In testimony whereof, I have hereuntoV 

